from overseas. pistole won't be comfortable until they get it all. >> we know that terrorists are looking for opportunities. to exploit any gaps in our security. >> reporter: the security gap is narrower than ever, but far from closed. for "good morning america," lisa stark, abc news, dulles, virginia. well frrngs danger in the zis danger in the water, there's been a surge of shark sightings in the northeast. it's been so bad off of cape cod, scientists are trying to track and tag them. jeremy has been following this story. >> yesterday alone, eight more great white sharks spotted off cape cod, on top of several other sightings in the last few days. with the help of airplanes, boats, and harpoon guns, researchers are getting answers. nearly a dozen great whites spotted off the shore of cape cod in the last week alone. now on this one beach, swimming is banned indefinitely. >> a little fearful. they're great whites after all.